From: Jon Mason <jdmason@xxxxxxxxxx> Have the GART_IOMMU help text specify that this is the hardware IOMMU in amd64 processors. This will be significant if/when other IOMMUs are added to the x86-64 architecture. :-) Also, note that the previous help text stated that IOMMU was needed for >3GB memory instead of >4GB. This is fixed in the newer version. Thanks, Jon Signed-off-by: Jon Mason <jdmason@xxxxxxxxxx> Signed-off-by: Andi Kleen <ak@xxxxxxx> --- arch/x86_64/Kconfig | 16 +++++++++------- 1 files changed, 9 insertions(+), 7 deletions(-) Index: linux/arch/x86_64/Kconfig =================================================================== --- linux.orig/arch/x86_64/Kconfig +++ linux/arch/x86_64/Kconfig @@ -364,13 +364,15 @@ config GART_IOMMU select SWIOTLB depends on PCI help - Support the IOMMU. Needed to run systems with more than 3GB of memory - properly with 32-bit PCI devices that do not support DAC (Double Address - Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter. - Normally the kernel will take the right choice by itself. - This option includes a driver for the AMD Opteron/Athlon64 northbridge IOMMU - and a software emulation used on other systems. - If unsure, say Y. + Support for hardware IOMMU in AMD's Opteron/Athlon64 Processors + and for the bounce buffering software IOMMU. + Needed to run systems with more than 3GB of memory properly with + 32-bit PCI devices that do not support DAC (Double Address Cycle). + The IOMMU can be turned off at runtime with the iommu=off parameter. + Normally the kernel will take the right choice by itself. + This option includes a driver for the AMD Opteron/Athlon64 IOMMU + northbridge and a software emulation used on other systems without + hardware IOMMU. If unsure, say Y. # need this always enabled with GART_IOMMU for the VIA workaround config SWIOTLB - : send the line "unsubscribe linux-x86_64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
